JPH0243412A - Pile with bag - Google Patents

Abstract

PURPOSE:To strengthen the fixing of bags to a ready-made pile by forming two bag-mounting portions provided on the pile into nearly right angled triangular sectional forms mutually facing toward opposite directions. CONSTITUTION:Bag-mounting portion are formed so that they consist of plural uneven constructions of triangular cross section and an apex of the protruding portion 8 of each triangle is lower than the surface of a straight portion 5 of a pile 1. In this instance, an angle alpha1 formed by the sides having the apex of the protruding portion of the triangle and the straight portion 5 is formed to be over 90 deg., favorably 90 deg. for a side 9 on the side distant from the center part of a bag-body. For a side 10 on the side close to the center part of the bag-body, an angle alpha2 is taken to be larger than alpha1, favorably 170 deg.. The forms of the two bag-mounting portions A, B provided on the pile-body 1 thus become face-symmetrical around the center part of the bag-body.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a pile with a bag used as a foundation pile for use in architecture and civil engineering structures (prior art and its problems). Piles that can be constructed in narrow spaces and have high bearing capacity have been developed as building foundations for narrow spaces such as urban areas. As shown in FIG. 4, for example, this pile had a cloth bag body (hereinafter simply referred to as a bag body in the present invention) 2 attached to the outer periphery of the tip of a ready-made pile 1. Such a pile is shown in, for example, Japanese Unexamined Patent Publication No. 10325/1983.

This pile has a structure that allows cement milk under a certain pressure to be injected into the bag through an injection pipe installed in the hollow part of the pile after being embedded in a pre-drilled hole at a predetermined depth in the soil. It has become.

Unexamined Japanese Patent Publication No. 6
2-291321, etc., it has been proposed to make the entire area of the ready-made pile where the bag body is present. However, the adhesion between the ready-made pile and the bag body has not been improved.

That is, the structure of this part is such that the bag body 2 is attached to the ready-made pile 1 by the belt 4 via the adhesive 11 and the cushioning material 12 on the outer periphery of the surface of the ready-made pile 1.

However, piles with such a fixed structure use adhesives in the process of attaching the bag to the ready-made pile, which can leave workers in a poor environment and reduce work efficiency due to the complexity of the process. Ta.

In addition, there were variations in adhesive strength, and the bag could come off from the ready-made pile when cement milk was poured during pile construction, which also affected the variation in the quality of pile construction.

(Means for Solving the Problems) An object of the present invention is to eliminate the drawbacks of these conventional techniques and to provide a pile having a structure that can more securely fix the bag and the ready-made pile.

That is, the present invention provides a pile with a bag body in which a cloth bag body is fixed to the ready-made pile at two attachment parts provided on the outer periphery of the ready-made pile, and the surface of the attachment part has a large number of triangular cross sections. It has an uneven structure, and the apex of the convex part is lower than the surface of the straight part of the ready-made pile, and each of the two sides of the triangular cross section of the convex part is the surface of the straight part of the ready-made pile. Each of the angles is characterized in that the angle α1 formed with the side farther from the center of the bag is 90° or more, and the angle α2 formed with the side closer to the center of the bag is larger than α1. It is a pile with a bag body.

Hereinafter, the present invention will be explained in detail using the drawings.

FIG. 1 is a half-sectional view showing a state when a consolidating fluid is press-fitted into a pile according to an embodiment of the pile with a bag according to the present invention.

In Fig. 1, the prefabricated pile 1 is attached by attaching the bag body 2 to the prefabricated pile 1 with a belt. It is fixed at 4.

When a cement-based solidifying fluid 3 is injected into the bag of this pile, the injection pressure is, for example, 3 kgf/c- to 12 kg.
The water in the caking fluid is dehydrated through the bag surface by the injection pressure of f/cd, and the caking fluid becomes a dense and strong hardened body after hardening. In addition, FIG. 3 shows an enlarged view of the fabric portion C when the bag shown in FIG. 1 is made of textile fabric. 30kgf/a*~119kgf per unit
A force of 51 kgf/cm to 204 kgf/cm is applied per unit width when attaching the bag to the antibody. As described above, the force applied to the bag when injecting the solidifying fluid exhibits a high value at the attachment point.

Therefore, in the present invention, as shown in FIG. 2, the mounting section has a special structure.

That is, the surface of the attachment part has a concavo-convex structure with a triangular cross-section consisting of a plurality of concave parts, and the apex of the convex part 8 is lower than the surface of the straight part 5 of the pile, that is, the top of the convex part 8 is lower than the surface of the straight part 5 of the pile. The difference between the height h2 to the surface of the straight part and the height hl from the bottom of the recess to the top of the convex part is as low as 2-5 m.

The cross-sectional triangle of the convex portion is an acute triangle, and the angles that each of the two sides of this triangle make with the surface of the straight portion 5 of the stake are the angles made with the side 9 on the side far from the center of the bag.
α1 is 90° or more, and the angle α2 formed with the side 10 on the side closer to the center of the bag is larger than α.

The angle α1 is, for example, 90-104°, preferably 90°, and the angle α2 is, for example, 166-172'.
, preferably 170°.

In this way, the two attachment parts A and B provided on the antibody have triangular cross-sectional shapes facing in opposite directions. In addition, in FIG. 2, the farthest part of the attachment part from the center of the bag body may not have a triangular cross section and may be a flat recessed part 7.

The length 2 of this attachment part is, for example, about 100-300 mm. Furthermore, for boat fishing, the pitch P of the uneven structure having a triangular cross section is 20-60 mm, and the height h+ between the bottom of the recess and the apex of the convex part of the uneven structure is 5-8M.

The number of triangular protrusions at one mounting point is 2-
The number is about 15, preferably 4-5.

The bag body 2 (
Particularly preferably, a water-permeable cloth bag 2) is placed over the bag, and a belt 4 is wrapped around the bag as shown in FIG. It is particularly preferable to fix the bag 2 to the antibody 1 by pulling.

In addition, the force for pulling the belt is determined by the injection pressure at the time of press-fitting the solidifying fluid from 3 kg f/cJ to 12 kg f/cJ.
In the case of c+il, it is preferable to tighten at 880 kgf to 3500 kgf. This tightening may be realized as a total force of one or more belts.

The belt used in this case is, for example, of relatively high strength, with a width of 10 mm to 60 mm and a thickness of 1 mm to 3 mm.
III11 is preferably used. Also, when installing in one place, you can use any number of belts per unit, but 2
It is common to use this book.

(Example) The piles used in the examples have the structure shown in FIG.

The diameter Di of the ready-made pile 1 is 350 mm, and the length of the ready-made pile is 3 m. The shapes of parts A and B for installation are as follows. That is, for installation, the length l of the section of the shaped part is 150 mm, the pitch of each triangle is 30 mm, the height h2 from the bottom of the recess to the surface of the ready-made pile is 10 mm, and the height hl from the bottom of the recess to the apex of the convex part is It is 5.

The angle α of the triangular cross section is 90@ and α2 is 170@. In addition, a PVC pipe with a diameter of 1 inch is arranged as an injection pipe 13 in the center of the hollow part of the pile, and this PVC pipe is connected to the inside of the bag in a T-shape so that cement milk can be injected into the bag body through this PVC pipe. It has a part.

The material of the bag body 2 was nylon 66, which had a tensile strength of 700 kgf per 3c+++ width. The bag used had a diameter Do of 600 m and a length of 2200 mm after cement milk was injected.

Using such a ready-made stake and a bag body, the above-mentioned installation is carried out by setting the bag body in the section and inserting two rows of steel strips from above the bag body.
The bag was fixed to the ready-made pile by tightening with a tensile force of ookgf to obtain the bag-equipped pile of the present invention.

Make 10 of these piles and bury them in the ground.
5! /min squeeze pump was connected to the PVC pipe, and the cement milk was press-fitted into the bag. As a result, the injection pressure for all 10 bottles was 12 kg/cJ, and a predetermined amount of cement milk could be injected into the bag. When the bag was attached to a prefabricated stake, no dislodging or shifting was observed.

On the other hand, for comparison, using ready-made piles shown in Figure 4,
Ten piles were made using adhesive and cushioning material and tightened with a steel band under the same conditions as in the example, and the injection test was conducted in the same manner as in the example. As a result, when the injection pressure reached 6 kg/c IIY, the bag partially detached from between the belt and the stake, and the injection pressure increased to 12 kg/c! There were few cases of ll.

In addition, tests were also carried out using ready-made stakes with simply recessed sections for attaching the bag. As a result, when the injection pressure reached 10 kg/+: fl, there were cases in which the bag partly separated from between the belt and the stake.

As described above, the strength of the bag-attached portion of the pile exploded using the method of the present invention was improved to twice that of the pile using the conventional method. Moreover, in normal pile construction, the cement milk injection pressure is designed to be 5 to 6 kg/c+fl, which proves that the expanded bulb pile (Fig. 1) formed by cement milk injection can be stably constructed. It was done.

(Effects of the Invention) In the pile with a bag of the present invention, the ready-made pile and the bag are securely and firmly fixed due to the special structure of the bag attachment part, so the injection pressure of the solidifying fluid is high. Even if the bag reaches a certain value, there will be no risk of the bag becoming detached from the stake. Therefore, the upper limit for controlling the injection pressure of the solidifying fluid becomes higher, the safety for the injection pressure design value (design at the time of construction (fi) is improved, and injection pressure management becomes very easy. The bag body installation work is also greatly improved by simplifying the process and improving the work environment.On the other hand, the entire bag body attachment part is recessed from the surface of the straight part of the pile, and a part of the friction cutter installed at the tip of the pile and excavation are removed. Since it is smaller than the diameter of the hole, it also has the effect of preventing the bag attachment part from coming into contact with the excavated hole, etc.

[Brief explanation of the drawing]

FIG. 1 is a half-sectional view when a solidifying fluid is press-fitted into an embodiment of the pile with a bag according to the present invention and the bag is expanded and expanded. FIG. 2 is an enlarged sectional view of the mounting section of FIG. 1. FIG. 3 is a partially enlarged view of the bag C shown in FIG. 1. FIG. 4 is a half-sectional view when a consolidating fluid is press-fitted into a conventional pile with a bag and the bag is expanded and inflated. DESCRIPTION OF SYMBOLS 1... Ready-made pile, 2... Cloth bag, 3... Consolidating fluid, 4... Belt, 5 Pile body straight part,
6...Outer circumference, 7...Flat recess, 8...Protrusion with triangular cross section, 9...One side on the far side, 10...One side on the near side, 11...Adhesive, 12 ...Cushidan material, 13...Injection pipe, 14...Warp thread, 1
5...Weft, 16...Friction cutter
α,・α2...The angle formed by the surface of the straight part of the antibody and each side of the convex part of the triangular cross section,! ...Length of the mounting part,
A...Top mounting is part, B...Bottom mounting is part, C.
... Bag fabric part, P ... Pitch between convex parts, Di.
...Outer diameter of ready-made pile, Do...Outer diameter of enlarged part.

Claims (1)

[Claims] A pile with a pair of bags in which a cloth bag body is fixed to two attachment parts provided on the outer periphery of the ready-made pile, and the surface of the attachment part has an uneven structure with a large number of triangular cross-sections. The apex of the convex portion is lower than the surface of the straight portion of the ready-made pile, and the angle that each of the two sides of the triangular cross-section of the convex portion makes with the surface of the straight portion of the ready-made pile is A pile with a bag body, characterized in that an angle α_1 formed with one side on the side farther from the center part is 90° or more, and an angle α_2 formed with one side on the side closer to the center part of the bag body is larger than α_1.